PROJECT SUMMARY/ABSTRACT Dystonia is a hyperkinetic movement disorder characterized by repetitive pulling movements and abnormal postures. Primary (isolated) dystonia is the third most common movement disorder, is often progressive and disabling. Adequate therapies for this illness are needed as there is not yet a cure. The available drug treatments are only symptomatic in nature, frequently associated with incomplete symptom relief and significant side effects. Deep brain stimulation (DBS) surgery can be a life altering symptomatic treatment for some persons with dystonia, but in others there is little benefit. The determinants of a good response to DBS are not known. Poor benefit following DBS may be due to heterogeneity in the genetic etiology and variability in the clinical presentation of dystonia. This project will address these knowledge gaps, focusing on identifying those factors associated with satisfactory clinical outcomes in dystonia. I will take advantage of a unique population to investigate these questions: the data repository of the Bachmann-Strauss Dystonia and Parkinson Foundation (BSDPF) Centers of Excellence Consortium, a repository of data on DBS dystonia patients from four U.S. centers, with the common goal of sharing clinical, genetic, motor physiology and imaging data. This dataset includes our well-characterized DBS treated dystonia population at UCSF, one of the largest populations of surgically-treated people with dystonia world wide. This project focuses on understanding how genetic causes and phenotype of dystonia predict motoric benefit. In the larger coalition population, all DBS cases from four experienced DBS centers will be screened for known mutations and genetic modifiers, and longitudinal surgical motor and disability rating scales will be compared among different mutations and phenotypes with the goal of determination of specific characteristics associated with greatest improvement. The results from this study will allow us to understand important factors that underline responsiveness to DBS, information that is critical to designing the most effective personalized treatments in dystonia. This proposed research project fits nicely with my long-term career goal of becoming a neuroepidemiology expert in developing personalized therapeutics for dystonia and other movement disorders. My training plan in this award includes course work and extensive mentored tutorials to further develop my epidemiological research skills and clinical trial methodology, and increase my knowledge of DBS mechanisms and human genetics. The knowledge and training acquired from this award will allow me to emerge as a leader in this evolving field of individualized precision medicine and address relevant unmet needs in dystonia.